Voltage

[cyclenut1952]

Hi, as a new ebiker I am just getting to charging batteries, when fully charged the using a volt meter it reads 41.6 not
42 volts.
Also the chargers only show 41.6
Am I completely not understanding battery voltage or should they read 42 volts when charged.
Thanks for any clarity.

 

[Woosh]

don't worry about the small difference, 41.6V is perfectly good.

 

[cyclenut1952]

Many thanks, bit of a worrier.

 

[Nealh]

The charger if only reading 41.6v output is a bit low and should read 42v to allow complete balancing to take place by the BMS, most chargers have an internal voltage pot that can be minutely adjusted to give the required 42v output.
Once the battery can supply 42v then it is for the battery BMS to allow the balance charge that may begin at 41.5 - 42v.
A simple adjustment can be made to the charger ( typical plastic case ones) by undoing the the 4 screws on the bottom often under the rubber plugs of the feet.

 

[cyclenut1952]

Thank you

 

[Benjahmin]

It could be the meter not reading accurately. Unless it has been checked (calibrated) against a known source, it has to be suspect. The important thing is that charger and battery both have the same reading with the same meter.
I have two batteries with different chargers, both read 41.6v with my meter and 41.7v with a second meter I have.

 

[cyclenut1952]

That’s reassuring, thank you, as a novice there seems a lot to know.